1. Field of the Invention
The present invention relates to an optical head and an optical disk apparatus capable of reading information from an optical disk by using lights of three wavelengths.
2. Description of the Related Art
In order to improve a recording density of an optical disk, a wavelength of a light used for reading/writing of information from the optical disk is becoming short. As a result, for the optical disk, there coexist different standards in which wavelengths different from each other are used. In other words, as the optical disk standards, there exist a CD, a DVD, an HD-DVD and the like in which an infrared light, a red light, and a blue light are used, for example. It is convenient if such optical disks of a plurality of standards can be read/written by a single optical disk apparatus. Accordingly, an optical disk apparatus capable of using lights of three wavelengths are developed (for example, see JP-A 2005-339718 (KOKAI)).